The invention described herein generally relates to Software Defined Radios (SDR) and SDR systems. In particular, a system and method of providing automated availability and integrity verification for software defined radios is described.
Software Defined Radio methodology is rapidly gaining favor as a way to architect and design radio communication systems with greatly improved interoperability and ability to accommodate future waveform variants. SDR refers to wireless communication in which the transmitter modulation is generated or defined by a computer, and the receiver uses a computer to recover the signal intelligence. To select the desired modulation type, the proper programs are run by microcomputers that control the transmitter and receiver.
A typical voice SDR transmitter, such as may be used in mobile two-way radio or cellular telephone communication, include the following stages: Microphone; Audio amplifier; Analog-to-digital converter (ADC) that converts the voice audio to digital data; Modulator that impresses the digital intelligence onto a radio-frequency (RF) carrier; Series of amplifiers that boosts the RF carrier to the power level necessary for transmission; and Transmitting antenna. Typically, the ADC and Modulator functions are carried out by computer-controlled circuits whose parameters are determined by software, in an SDR.
A typical receiver designed to intercept the above-described voice SDR signal may employ the following stages, essentially reversing the transmitter's action: Receiving antenna; Superheterodyne system that boosts incoming RF signal strength and converts it to a lower frequency; Demodulator that separates the digital intelligence from the RF carrier; Digital-to-analog converter (DAC) that generates a voice waveform from the digital data; Audio amplifier; and Speaker, earphone, and/or headset. Typically, the demodulator and DAC functions are carried out by computer-controlled circuits whose parameters are determined by software, in an SDR.
The most significant asset of SDR is versatility. Wireless systems employ protocols that vary from one service to another. Even in the same type of service, for example, cellular telephones, the protocol often differs from country to country. A single SDR set with an all-inclusive software repertoire may be used in any mode, anywhere in the world. Changing the service type, the mode, and/or the modulation protocol involves simply selecting and executing the requisite computer program. The ultimate goal of SDR engineers is to provide a single radio transceiver capable of playing the roles of cordless telephone, cell phone, wireless fax, wireless e-mail system, pager, wireless videoconferencing unit, wireless Web browser, Global Positioning System (GPS) unit, and other functions to be later developed, operable from any location on the surface or proximate the surface of the earth, and perhaps in space as well.
The United States Department of Defense (DoD) Joint Tactical Radio System (JTRS) initiative has established an Open Standard Architecture for implementation of military communication waveforms that is specifically intended to meet a subset of these objectives. Such Joint Tactical Radio Systems are available from Rockwell Collins, Inc. of Cedar Rapids, Iowa.
There is growing interest in applying an Open Standard SDR Architecture to commercial applications such as avionics communication, navigation and surveillance (CNS). The characteristics of commercial CNS waveforms are quite different from the military JTRS communication waveforms, and, in general, are less complex to implement. A key difference between military communications and commercial avionics are the requirements associated with safety. The safety requirements associated with commercial CNS avionics typically involve gaining approval for use (generally referred to as “certification”) by the appropriate civil aviation authority, such as the Federal Aviation Administration (FAA) in the United States or the Joint Aviation Administration (JAA) in Europe. The safety requirements for the CNS functions typically address the integrity and availability, and for some functions, the continuity. Thus, it is desirable to provide an avionics commercial CNS system architecture that addresses the safety requirements while retaining compatibility with an appropriate SDR standard, preferably the Open Standard Architecture established by the DoD as part of the JTRS program.
In particular, there is a need for SDR technology that allows a single set of hardware to perform multiple functions by software reconfiguration. Further, there is a need for reconfigurable systems that automatically and autonomously verify the availability and integrity of a reconfigured SDR using available SDR resources. Further still, there is a need for such a reconfigurable system that satisfies certification requirements with a robust means to automatically and autonomously verify the availability and integrity of the reconfigured SDR using available SDR resources.